A colour used in make up for appearance (5)
I believe the answer is:
atone
'make up for appearance' is the definition.
'atone' can be an answer for 'make' (thesaurus). I am not certain of the 'up for appearance' bit.
'a colour' is the wordplay.
'colour' becomes 'tone' (tone can mean a colour or shade).
'a'+'tone'='ATONE'
'used in' acts as a link.
Can you help me to learn more?
(Other definitions for atone that I've seen before include "Make amends, being at one" , "Recompense" , "In agreement - sounds singular" , "Make up, compensate (for)" , "Make redress" .)